I got Dex a cave because he's been sleeping under his plants. I did a partial water change when I added the cave, and moved his plants around to make room for it. When I came home from class today his fin looked completely shredded!! Is it fin rot or did he tear it up on the cave?? I was very careful about checking for sharp edges when I picked his cave out. I have already removed the cave to prevent further damage. Is there anything I can do to help him? He is still swimming around like normal
I will post an image in just a minute, I just need to upload it somewhere first

http://i245.photobucket.com/albums/g...AED7959F3E.jpg
Ok that is the picture. The red coloring on his fin is normal, it's been like that since I got him. His nitrate and nitrite levels are low enough that my test didn't pick them up and the pH is 7.2. Anything you could tell me would he helpful, I'm really worried about him ):